On average, research suggests, a person’s weight is probably at it more than 50 person influenced by genetic factors. However, in certain populations the environment plays a larger role. When you see a family in which every member is slim. You may be wonder and question comes in your mind. Are they svelte because they are genetically programmed to be or because they go on family hikes and never set foot in a Burger King? The influence of genetics and the environment on weight is an issue that scientists have been trying to sort out for decades.
A wealth of knowledge has come from research on identical twins, who, of course, share all the same genes. In a classic Canadian study published in the New England Journal of Medicine, researchers sequestered 12 sets of identical male twins for 100 days at a college dorm. Six days a week, the twins were fed 1,000 calories per day more than they needed to maintain their weight. Other than walking for 30 minutes daily.
The subjects performed virtually no physical activity. At the end of study each subject had consumed 84,000 extra calories enough, theoretically to gain about 24 pound. Also since it generally takes an extra 3,500 calories to gain 1 pound of fats. But that’s not what happens to some men gained as little as 9.5 pounds, whereas others gained as much as 29 pounds. The difference in weight gain among the various twin pairs was three times greater than the average difference within the pairs.
The location of the extra fat deposited whether below the waist, deep in the belly, or beneath the skin the abdominal area also was similar within the pairs but varied greatly between pairs. Moreover, research comparing twins raised apart and twins raised together confirms the significant influence of genes on body dat. In a study of some 600 Swedish twins, the body mass index scores of identical twins raised apart were just as similar as BMI scores of identical twins raised together.
And the BMI scores within the identical twin pairs were far more similar than the BMI scores within the fraternal twin pairs. The researchers concluded that, at least in Western society, genetic factors may accounts for as much as 70 percent of weight difference among individuals. So does this mean your weight is essentially predetermined? So absolutely not! Sure, if you are genetically susceptible to obesity and your idea of a workout is lifting the lid off a bucket of KFC chicken, you will likely be heavier than a fellow ouch potatoes/KFC fiend who has a propensity to be lean. But if you take up cycling and switch from fried chicken drumsticks to skinless baked breasts, you are likely to stay at a healthy weight regardless of your genes.
Someone who has susceptibility toward obesity just has to be more careful. The rising obesity levels over the last generation show that eating habits and activity levels can drastically affect body weight. Our genes haven’t changed that fast, but our environment has. In certain regions, environmental influences are expressed more fully than in others. It is primarily lifestyle differences that explain why only 13.8 percent of Colorado residents are obese compared with 24.3 percent of Mississippians. However, it is largely genetic differences that explain why certain Native American populations have higher obesity rates than other Americans with similar habits. Source: CP
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